kernel: drop mips highmem offset start overrides

The maximum offset that can be supported is 0x20000000
Do not override it to to something bigger than that on MT7621, as that could
cause issues based on the fixed memory mappings. This makes the last 64 MB
RAM unusable on MT7621 devices with 512 MB but avoids incurring a heavy
performance hit

Fixes: cd2b74e01e8d ("ramips: mt7621: disable highmem support and remove highmem offset patch")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
(cherry picked from commit a110de8152df46a1e2adf7010ba75fb3b1236cd8)

diff --git a/target/linux/generic/pending-5.15/307-mips_highmem_offset.patch b/target/linux/generic/pending-5.15/307-mips_highmem_offset.patch
deleted file mode 100644 (file)
index 0529b0c..0000000
--- a/target/linux/generic/pending-5.15/307-mips_highmem_offset.patch
+++ /dev/null
@@ -1,19 +0,0 @@
-From: Felix Fietkau <nbd@nbd.name>
-Subject: kernel: adjust mips highmem offset to avoid the need for -mlong-calls on systems with >256M RAM
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
- arch/mips/include/asm/mach-generic/spaces.h | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
---- a/arch/mips/include/asm/mach-generic/spaces.h
-+++ b/arch/mips/include/asm/mach-generic/spaces.h
-@@ -46,7 +46,7 @@
-  * Memory above this physical address will be considered highmem.
-  */
- #ifndef HIGHMEM_START
--#define HIGHMEM_START         _AC(0x20000000, UL)
-+#define HIGHMEM_START         _AC(0x10000000, UL)
- #endif
- 
- #endif /* CONFIG_32BIT */

diff --git a/target/linux/ramips/patches-5.15/120-highmem-start-offset.patch b/target/linux/ramips/patches-5.15/120-highmem-start-offset.patch
deleted file mode 100644 (file)
index 629c7bf..0000000
--- a/target/linux/ramips/patches-5.15/120-highmem-start-offset.patch
+++ /dev/null
@@ -1,19 +0,0 @@
-From: Felix Fietkau <nbd@nbd.name>
-Date: Mon Jul 24 13:29:13 CEST 2023
-Subject: [PATCH] mips: ralink: increase highmem start
-
-Increase highmem start address in order to support devices with 512 MB memory
-and MT7621 SoC
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
---- a/arch/mips/include/asm/mach-ralink/spaces.h
-+++ b/arch/mips/include/asm/mach-ralink/spaces.h
-@@ -5,6 +5,7 @@
- #define PCI_IOBASE    _AC(0xa0000000, UL)
- #define PCI_IOSIZE    SZ_16M
- #define IO_SPACE_LIMIT        (PCI_IOSIZE - 1)
-+#define HIGHMEM_START   _AC(0x24000000, UL)
- 
- #include <asm/mach-generic/spaces.h>
- #endif